What setback is required from non-perforated distribution lines?

The correct answer indicates that there is no setback required from non-perforated distribution lines. This means that non-perforated distribution lines can be placed without a specified distance from certain features, such as property lines or water sources. Non-perforated distribution lines are used primarily to convey wastewater without allowing any effluent to leach out into the surrounding soil, which is crucial for maintaining proper filtration and preventing contamination of groundwater or surrounding areas.

The absence of a setback requirement for these lines is based on the understanding that they are intended to keep wastewater contained, preventing it from impacting the environment. This characteristic of non-perforated lines differentiates them from perforated distribution lines, which do have specific setback requirements due to their role in distributing effluent into the surrounding soil for further treatment and absorption.

In contrast, the other options suggest certain distances that would imply potential environmental risks or regulatory requirements associated with the placement of these lines. Therefore, recognizing that no setback is necessary for non-perforated distribution lines underscores their unique function in septic system design and their regulated operation to aid in effective wastewater management.